Sights lowered on wildlife benefits from organic farming

The benefits to wildlife and increases in biodiversity from organic farming are much lower than previously thought, according to research.

Organic farms may be seen as wildlife friendly, but the benefits to birds, bees and butterflies do not compensate for the lower yields produced, according to research by the University of Leeds.

Experts from the Faculty of Biological Science carried out detailed, like-for-like comparisons of organic and conventional farming.

The research found organic farms had, on average, 12 per cent more biodiversity in terms of the number and variety of plants, birds, earthworms and insects.

However, the organic farms in the study produced less than half of the yield of their conventional counterparts, according to the results which are published online in Ecology Letters.

"Over the next 40 years, we're going to have to double food production worldwide to keep pace with population increases," says Tim Benton, who led the project.

"Our results show that to produce the same amount of food in the UK using organic rather than conventional means, we'd need to use twice the amount of land for agriculture.

"As the biodiversity benefits of organic farming are small, then the lower yield may be a luxury we can't afford, particularly in the more productive areas of the UK."

The Leeds project, funded under the Rural Economy Land Use programme, aimed to see if organic farming was still as good for wildlife if these landscape effects were taken out of the equation.

The research looked at two areas in Central South West England and the North Midlands, taking into account over 30 variables covering climate, topography, socio-economic conditions, land use and soil type.

Thirty-two organic and non-organic farms were paired together, some in "hotspot" regions with many organic farms and others in "coldspots" with very few, to help identify any cumulative impacts over a wider area.

Comparisons were made also between individual fields, with 192 fields sampled in all.

Comparing farm by farm, the researchers found a 55 per cent drop in yield compared to a 12.4 per cent increase in biodiversity.